Tuesday, February 24, 2009

What's all the noise about?

One of the best definitions I have found for noise pollution (environmental noise) is:

Noise pollution is a type of energy pollution in which distracting, irritating, or damaging sounds are freely audible. As with other forms of energy pollution (such as heat and light pollution), noise pollution contaminants are not physical particles, but rather waves that interfere with naturally-occurring waves of a similar type in the same environment. Thus, the definition of noise pollution is open to debate, and there is no clear border as to which sounds may constitute noise pollution. In the most narrow sense, sounds are considered noise pollution if they adversely affect wildlife, human activity, or are capable of damaging physical structures on a regular, repeating basis. In the broadest sense of the term, a sound may be considered noise pollution if it disturbs any natural process or causes human harm, even if the sound does not occur on a regular basis. --more

An EPA press release dated April 2, 1974 stated:

"Noise levels requisite to protect public health and welfare against hearing loss, annoyance and activity interference were identified today by the Environmental Protection Agency. These noise levels are contained in a new EPA document, "Information on Levels of Environmental Noise Requisite to Protect Public Health and Welfare with an Adequate Margin of Safety."

One of the purposes of this document is to provide a basis for State and local governments' judgments in setting standards. In doing so the information contained in this document must be utilized along with other relevant factors. These factors include the balance between costs and benefits associated with setting standards at particular noise levels, the nature of the existing or projected noise problems in any particular area, the local aspirations and the means available to control environmental noise."

It should be noted that the EPA does not have any regulatory authority governing noise in local communities. In the past, EPA coordinated all federal noise control activities through its Office of Noise Abatement and Control. In 1981, the Administration at that time concluded that noise issues were best handled at the state or local government level. As a result, the EPA phased out the office's funding in 1982 as part of a shift in federal noise control policy to transfer the primary responsibility of regulating noise to state and local governments. The Noise Control Act of 1972 and the Quiet Communities Act of 1978, however, were not rescinded by Congress and remain in effect today, although essentially unfunded.

Also note that all federal noise regulations remain in effect, and are enforced by either EPA or a designated federal agency. These regulations cover standards for transportation equipment, motor carriers, low-noise-emission products, and construction equipment.

Louis Hagler, MD, in his Summary of Adverse Health Effects of Noise Pollution, lists seven categories of adverse health effects of noise pollution on humans. As documented by the World Health Organization they are:
  1. Hearing Impairment
  2. Interference with Spoken Communication
  3. Sleep Disturbances
  4. Cardiovascular Disturbances
  5. Disturbances in Mental Health
  6. Impaired Task Performance
  7. Negative Social Behavior and Annoyance Reactions
Given that humans are biological organisms, is it safe to say that the above adverse effects would affect all biological organisms? If not, why not?
The Noise Pollution Clearinghouse published a fact sheet entitled Noise Effects on Wildlife. It reads as follows:
Sources of noise that have the potential to effect wildlife include aircraft overflights, recreational activities such as snowmobiling and motorboating, automobile traffic, and heavy machinery and equipment. The effects of aircraft noise have been studied more intensively because of their threat to wildlife populations in national and state refuges and parks. Impacts to wildlife habitat in remote areas have increased from military aircraft overflights and helicopter activity related to the tourism and resource extraction industries (National Park Service, 1994).
The study of animal response to noise is a function of many variables including characteristics of the noise and duration, life history characteristics of the species, habitat type, season and current activity of the animal, sex and age, previous exposure and whether other physical stressors (e.g. drought) are present (Manci, et al., 1988).
Physiological responses: Disturbances from aircraft noise range from mild, such as an increase in heart rate to more damaging effects on metabolism and hormone balance. Long term exposure to noise can cause excessive stimilation to the nervous system and chronic stress that is harmful to the health of wildlife species and their reproductive fitness (Fletcher, 1980; 1990).
Behavioral responses: Responses vary among species of animals and birds and among individuals of a particular species. Variations in response may be due to temperament, sex, age, and prior experience with noise. Minor responses include head-raising and body-shifting. More disturbed mammals will trot short distances; birds may walk around flappping wings. Panic and escape behavior results from more severe disturbances (National Park Service, 1994).
Behavioral and physiological responses have the potential to cause injury, energy loss (from movement away from noise source), decrease in food intake, habitat avoidance and abandonment, and reproductive losses (National Park Service, 1994). Studies have shown that when certain bird species are flushed from nests in response to noise, eggs are broken and young are exposed to injury and predators (Bunnell et al., 1981; Gladwin, 1987). Young mammals have been trampled as adults attempt to flee from aircraft (Miller and Broughton, 1974). Another study compared mortality rates of caribou calfs exposed to overflights to those not exposed (Harrington and Veitch, 1992). Mortality rates were significantly greater in the exposed group. Milk release may have been inhibited in mothers disturbed by the noise leaving calfs malnourished.
Animals rely on hearing to avoid predators, obtain food, and communicate. Auditory systems of some animals are particularly at risk to physical damage from chronic noise, for example desert animals that have evolved an acute sense of hearing. Studies have documented hearing loss caused from motorcycle noise in the desert iguana (Bondello, 1976) and the kangaroo rat, an endangered species (Bondello and Brattstrom, 1979)
Ninety-eight species of birds and mammals on national park lands have been identified as threatened or endangered. The impacts on these species from aircraft noise are largely undocumented. Some of the species became threatened or endangered because of loss of habitat. Further relocation necessary because of noise disturbance might not be possible for these species (National Park Service, 1994).
Studies are needed to determine the long term effects of noise disturbance. Long-term studies have been difficult because of the effort required and the complexity of the variables affecting animal survivorship (National Park Service, 1994).
The overwhelming focus of recent research seems to be on the effect of noise on marine mammals.
“Ocean noise is an invisible but potentially deadly form of pollution. IFAW is calling on governments to recognize ocean noise as a pollutant and act now to turn it down,” said Jorge Luis Basave, IFAW Asia Pacific Campaigner.
“Ocean noise has doubled in each of the past four decades. The world’s 100,000-strong commercial shipping fleet is the biggest single man-made noise generator - and by 2025 the gross cargo tonnage shipped internationally is forecast to double or even triple,” Mr Basave said.
While the favored target of most of the research seems to be on the military, the effect of increased shipping traffic cannot be overlooked. The fact that shipping lanes coincide with normal migratory routes for many species of marine mammals would contribute greatly to that effect.
Using information derived from the Coral Reef Temperature Anomaly Database (CoRTAD) and 16 other layers of data, Dr. Ben Halpern from the National Center for Ecological Analysis and Synthesis (NCEAS) at the University of California Santa Barbara (UCSB) and a team of researchers including NODC's Dr. Kenneth Casey published a paper in Science documenting human impacts on marine ecosystems.
The study reveals that over 40% of the world's oceans are heavily affected by human activities and few if any areas remain untouched. The project is the first global-scale study of human influence on marine ecosystems.
Bernie Krause, is a professional field recordist and bioacoustician. Krause has a word for the pristine acoustics of nature: biophony. In 40 percent of the locations where Krause has recorded over the past 40 years, human-generated noise has infiltrated the wilderness. "It's getting harder and harder to find places that aren't contaminated," he says.
Krause proposes that in a biophony, animals divide up the acoustic spectrum so they don't interfere with one another's voices. He states that no two species are use the same frequency. "That's part of how they coexist so well," Krause says. When they issue mating calls or all-important warning cries, they aren't masked by the noises of other animals.
When man-made noise — anthrophony, as Krause dubs it — intrudes on the natural landscape it interferes with a segment of the spectrum already in use, and suddenly some animal can't make itself heard. The information flow is compromised.
Krause brought biophony to the masses by creating an add-on for Google Earth. Download it from his WildSanctuary.com site and you can click on dozens of locations worldwide to hear snippets of their soundscape.
While the subject of environmental noise pollution and its effects on wildlife are still the subject of vigorous debate their is no doubt that our world has become increasingly noisy. With our technology expanding exponentially it seems like there should be a way for us to be less auditorily intrusive.
Until next time...become the change you imagine.


BP said...

You know one thing that I like about winter? It is to cold for the idiots across the street to get drunk then hang out in the road making noise all night. I hate to camping just to have someone else camp close and blast the radio. So much for nature and rest. I live in the city, but love to hear nature and peace.

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